对TextView的字数进行统计

import "ViewController.h"

define MAXVALUE 10

define MINVALUE 5

@interface ViewController ()

@property (nonatomic, strong) UITextView *textView;
@property (nonatomic, strong) UILabel *tipLabel;

@end

@implementation ViewController

• (void)viewDidLoad
  {
  [super viewDidLoad];

  self.textView = [[UITextView alloc] initWithFrame:CGRectMake(0, 60, self.view.frame.size.width, self.view.frame.size.width / 2)];
  self.textView.backgroundColor = [UIColor yellowColor];
  self.textView.returnKeyType = UIReturnKeyDone;
  self.textView.font = [UIFont systemFontOfSize:16.0f];
  self.textView.delegate = self;
  [self.view addSubview:self.textView];

  self.tipLabel = [[UILabel alloc] initWithFrame:CGRectMake(self.view.frame.size.width - 180, self.textView.frame.size.height + 110, 150, 50)];
  self.tipLabel.backgroundColor = [UIColor clearColor];
  self.tipLabel.font = [UIFont systemFontOfSize:12];
  self.tipLabel.text = [NSString stringWithFormat:@"字数不少于%d个字", MINVALUE];
  self.tipLabel.textAlignment = NSTextAlignmentRight;
  [self.view addSubview:self.tipLabel];

  UIButton *nextBtn = [[UIButton alloc] initWithFrame:CGRectMake(100, self.tipLabel.frame.origin.y + self.tipLabel.frame.size.height + 100, self.view.frame.size.width - 200, 50)];
  [nextBtn setTitle:@"下一步" forState:UIControlStateNormal];
  nextBtn.backgroundColor = [UIColor redColor];
  [nextBtn addTarget:self action:@selector(doBtn) forControlEvents:UIControlEventTouchUpInside];
  [self.view addSubview:nextBtn];
  }

• (void)doBtn
  {
  if (self.textView.text.length > MAXVALUE) {
  NSLog(@"可以弹一个toast，说明不能超过某个限制的数字");
  } else if (self.textView.text.length < MINVALUE){
  NSLog(@"可以弹一个toast，说明不能小于某个限制的数字");
  } else {
  NSLog(@"可以进行下一步");
  }
  }

• (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
  {
  if ([text isEqualToString:@"\n"]) {
  [self.textView resignFirstResponder];
  return NO;
  }

  return YES;
  }

• (void)textViewDidChange:(UITextView *)textView
  {
  UITextRange *selectedRange = [textView markedTextRange];
  //获取高亮部分
  UITextPosition *pos = [textView positionFromPosition:selectedRange.start offset:0];

  //如果在变化中是高亮部分在变，就不要计算字符了
  if (selectedRange && pos) {
  return;
  }

    NSUInteger count = textView.text.length;
    if (MINVALUE > 0 && count < MINVALUE) {
        self.tipLabel.text = [NSString stringWithFormat:@"字数不少于%d个字", MINVALUE];
    } else {
        self.tipLabel.text = [NSString stringWithFormat:@"%ld/%ld字", (unsigned long)count, (long)MAXVALUE];
    }
  

}

@end